In every tyrant’s heart there springs in the end this poison, that he cannot trust a friend.

Power held by force removes the possibility of being told the truth. Once everybody around you has reason to fear the consequences of honesty, you lose any way of knowing whether somebody is loyal or merely careful, and the suspicion that follows is less paranoia than an accurate reading of what you built. Isolation is the structural cost of ruling by fear.

Small versions exist in ordinary life. If you have made it expensive for people to disagree with you, at work or at home, you will stop hearing anything useful. Notice who has gone quiet around you and ask why.